Thermostat



Sepo lp 1939., G, WNSCH YZQ@ THERMOSTAT Filed July 9, 1929 @Mdo y sofof/zeg l Patented Sept. 1*-930 UNITED ,euri-2 5A PATNu curvo WNscr-r,onsrner.1'rz, NEAR BERLIN, 'eumtmisnr` THERMOSTAT l Application led July9, 1.929, Serial No. 376,967, and ln Germany July 7, 1928. I

The use of the known thermostatsbased on the expansion of a body forpurposes of temperature regulation has the disadvantage that it has beenimpossible. to effect a re- 5 placement without at the same timestopping the working of the apparatus. Such thermostats generally havebeen inserted in a flange of the pipe in which the temperature had to bemeasured and when the pipe carried for instance liquid, steam, gas, orthe like,'it was necessary to put the pipe out of action as an openingwas produced in the plipe vhen the thermostats were being reace p It hasalready been proposed to insert into the opening a tube which enclosesthe thermostat proper, but'which always remains in the space thetemperature of which is to be measured, even when the thermostat isreplaced. In this waythe thermostat can be replaced without interferingwith the working since the measuring tube closes the opening in thebody.

In the existing forms of such thermostats which are chiefly constitutedby a tube, such a considerable insulation would be produced by theprotective sleeve that the thermostat would work too slowly. This faultis avoided by the present invention by using the thermostat in theformof a very thin steel band namely of a thickness of a few hundredths of amillimeter and of a width of a few millimlters or in the form of steelwires or the 1i e.

The accompanying drawing shows by wa of example a construction.according to the invention in section.

In any desired chamber, in a pipe or the like 11 which is indicated inthe drawing by cross hatching, the protective tube 1 is inserted. Aflange `5 is used for holding -the tube which flange is secured forexample by screws 8 to the wall .of the chamber in which the measurementis to be effected. The thermostat proper, which is iitted into theprotective tube 1 comprises a body 9 having a flange 10 which closelyadjoins the flangeY 5, and may be replaceably connected `with the saidflange 5 or the wall 11 by means of screw- 50 bolts 12. The sensitivepart of the thermostat or the like.

of said stri is chieliy constituted by a steel band 2 which isvery thin,preferably less than 0.1 mm. and the width of'which amounts to only afew millimeters. The band is secured with both its ends to the body 9 ofthe thermostat and 55. its central part passes over a saddle-shapedsupport 6. This support is arranged on a rod 3 with which-a spring 4engages so that the rod or the su port 6 is always held in such a manneras to eep the steel band 2 taut. The go rod 3- is made of a materialsuch as for instance quartz, which does not expand at all or at leastnot toa perceptible de ree in heat. The expansion of the steel'ban underthe actin-of heat i's then transmitted in the usual ce manner throughthe rod 3, and the rod 7 fixed on rod 3 tor the device operated by thethermostat. This maybe for instance a pointer device, a writing device,a regulating device The essential point is that the` thermostat has anexceedingly small mass which, in spite of the protective tube 1, reactssuliicient- 1 quickly to fiuctuations of heat. Owing to the arran ementof the protective tube which 1Q protects t e thermostat from mechanicalinjurly, it is possible to use thin sensitive materia '1. A thermostatcomprising, in combinasu tion, a thin metal strip arranged in the formof a U a thermostat body to which the ends of sai strip are connected,means arranged on said body adapted to hold the strip taut ycomprising-a rod of a material having a relase tively low coefiicient ofexpansion, said rod engaging the closed end of said U-formed strip,means connected with said rod for transmitting the expansion of saidstrip and a protective tube adapted to be fitted into an opening of thecontainer in which the measur'ement is bein' effected and in which thesaid body is rep aceably inserted.

2. A thermostatcomprising, in combination, a thin metal strip arrangedinthe form of a U, a thermostat body to which the ends are connected,means arranged on said bo y adapted to hold the strip taut comprisingarod of 'a material having a relatively low coeilcient of expansion, saidrod engaging the closed end of said U-formed strip and a spring pressingsaid rod against the central portion of the strip, means connected withsaid rod for transmitting the expension of said strip `and a protectlvetube adapted to be tted into an opening of the container in which themeasurement 1s being effected and in which the said body is re-Yplaceablyinserted. w In testimony whereof Itaix my signature.

GUIDO wtJNscH.

